Mounting of electric insulators



' Jan. '25., 1938f v 1 vTHHQY 2,106,667

MOUNTING OF ELECTRIC INSULATORS Filed Nov. 8, 1934 lNVEN-rof 5 Z2 2g @-14l. ATTN.

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Patented Jan. 25, 1938 UNITED STATES .PATENT ori-ICE i MOUNTING FELECTRIC INSULaToRs Leon Thiry, Huy, Belgium application November s,1934, serial No. '151,933

2 Claims.

The present invention relates to the mounting of electric insulatorsupon their supports, and has chiefly for its object a device for themountlng of electric insulators which comprises a thick ring oy elasticmaterial adapted to be interposed between the insulator and the head oithe sup portingbracket, and assuring their connection.

Owing to this device, the vibrations and mechanical stresses which maybe accidentally exerted upon the insulator or the bracket, will have noprejudicial eifect upon their connection, and will not weaken the same.On the other hand, the vibrations received by one oi' these two membersare absorbed by the mass of elastic eter is equal to or somewhat lessthan the small est diameter oi the recess provided in the insu'- later,and then inserting the device consisting of the ring and bracket, andthe auxiliary member, into the body of the insulator.

Further characteristics ci the invention will be set :lorth in thefollowing description:

In the accompanying drawing, which is given solely by way of example:

Fig. l is a longitudinal section showing the mounting of an insulatorupon its bracket, ac-

cording to the invention.

Figs. 2 to i are views, analogous tol Fig. i, of various modications.

Fig. 5 shows, in longitudinal section, a method of mounting of theinsulator, according to the invention.

Fig. 6 is a longitudinal section of a ring of elastic material, inn thefree state, oi the type employed for the mounting of insulators,according to the invention.

Fig. 'I is a longitudinal section of the same ring, maintained in astateof deformation between two sleeves.

Fig. 8 is a view, analogous to Fig. 6, of the same ring, congealed whenin the state of deformation to which it has been brought.

According to the example of execution represented in Fig. 1, theinsulator I, made of porcelain, glass, or other suitableinsulatingmaterial, has a recess 2 adapted to receive a supporting bracket 3. Atthe upper end oi said recess 2 is mounted a washer 4 of elasticmaterial, which prevents all contact between the bracket 3 'and theinsulator l.

Aring 5 of elastic material. oi indiarubber Germany December 2, 1933 forexample, is mounted in the recess 2 and surrounds the bracket 3.

The connection between the ring d of elastic material and the bracket 3,and the insulator i, may be obtained by one of the following operations,or by a combination of several of these operations: by cementing, byvulcanising, by deformation of the elastic material between the bracketand the insulator (either by axial elongation, by compression andcircular expansion, or by both of these, and in general, by anydeformation in one or more specified directions), or by a spiralwinding, with or without elongation.

Owing to the presence of the ring 5 and of the washer of elasticmaterial between the bracket 3 and the insulator l, the vibrationsreceived by one of these two members cannot be imparted to the othermember, as they` are absorbed by the deformations of the elasticmaterial. On the other hand, this elastic material (usually ofindiarubber) is a goed electric insulator, and. thus the insulation ofthe insulator i with refern once to the bracket 3 is improved.

Fig. 2 represents another method oi realization of the invention, inwhich the washer d is eliminated, and` the ring 9 of elastic materialcomprises a closed end l separating the end of the bracket 3 from theend of the recess 2 of the insulator. This ring may be subject todeformation, and preferably by larial elongation and radial contraction,which also causes a deforman tion oi the end 1 of the said ring.

In the examples of execution represented in Figs. 3 and 4, the ring 5 ofelastic material is not in direct contact with the insulator i. .Asleeve 8, preferably ci a soft metal such as brass, is interposedbetween the ring 5 and the irisulator, The recess 2 of the insulator, inFigs. 3 and 4, has a conical shape, and the large base of the cone isnext the upper end of the recess, whilst the bracket 3 is cylindrical,and the cylindrical sleeve 8 has longitudinal slots 9 providing for itsexpansion under the eect of tensions of the ring 5 of elastic material.Thus the sleeve 8 is well applied against the innerwall of theinsulator, and owing to the conical shape of this wall, the ring cannotleave the insulator. One may also provide an elastic ring I0 located ina groove Il formed in the narrow part of the recess and adapted to stopthe sleeve 8.

The assembling of the insulator represented in Figs. 3 and 4 ispreferably eiiected in the following inanner. The sleeve 8 is placed ina ring l2 whose inner diameter is equal to or somewhat less than thesmallest diameter of the conical recess 2 oi the insulator (Fig. 5). Thering 5 of elastic material is then placed in the sleeve -8, and thisring receives the shank 3 of the bracket. A suitable choice is made ofthe dimensions of the ring` when in the free state, andof those of therod 3 and the sleeve l, so that the elastic material of the ring shallbe subjected to a great deformation between the sleeve and the shank.

The device thus formed is applied against the i insulator l, in such waythat the ring I2 shall iit against the lower part. I3 of the insulator(the outline of the external surface of this ring being in fact arrangedfor this purpose), and the whole device, sleeve 8, ring 5 and shank I,is fitted from the ring, I3 into the insulator I. Under the action ofthe molecular tensions of the ring I conssting of elastic materialsubjected to deformation, the slotted sleeve 3 will expand, andprincipally towards the upper end of the recess 2 at which the diameteris greater, and it will fit strongly against the wall of this recess.

Although it is possible to obtain a good adherence between the elasticring l and the nternal shank 3, either bythe deformation of the saidring, or by cementing or vulcanizing, there is also provided a stop, inorder to prevent the shank .i from moving lengthwise on the ring l (Fig.4). This stop may consist of a metallic washer i4 iitted into a groovein the end of the shank 3 ci the bracket and adapted to make contactwith the inner end of the elastic ring l.

One proceeds with the mounting oi' the stop washer M on the bracket 3,after securing this bracket in the elastic ring 5 and before insertingthe assemblage of the sleeve 8, the ring 5 and the bracket 3 into therecess 2 of the insulator. The washer it will come against the mass ofelastic material t interposed between the end oi' the recess 2 and thebracket 3. This mass 4 oi elastic material may be perforated, as shownin Fig. e.

It will be noted that the mounting of the elastic ring t between theinsulator i and the head 3 of the bracket will require certain specialprecautions on account of the fragility of the material constituting theinsulator, and in particular in the case in which the said ring is to beplaced in position in a state of deformation. This mounting may bereadily eected by operating in the following manner. The ring 5, in thefree state (Fig. 6), is inserted, by. known means, between two sleeves22 and 23 (Fig. 7) whose dlmensions are chosen with respect to thedimensions of the ring 5, in order to produce, in this latter, thedesired state of deformation.

ln the example represented in Fig. 7, this ring is elongated axially,but it is quite evident that it may be given any other deformation; forexample, a circular elongation may be given to said ring.

One then .roceeds with the congelation of the ring oi elastic materialwhich is thus maintained between the two sleeves.

The congemed ring thus obtained preserves the and thedimensions which ithad when it was maintained between the sleeves 22 and 21 (Fig. il), asunder the action of the low temperature, it has lost its elasticproperties. The said ring may thus be inserted, readily and withouteiort, between the body i of the insulator and the head 3 oi thebracket, the space provided between these members being somewhat largerthan the thickness oi' the congealed ring. When the temperature oi thering 5 rises, this ring, will gradually resume its elastic properties,and when its temperature reaches the surrounding temperature, theinternal elastic stresses of the said ring will cause it to adherestrongly to the walls of the members between which it is situated.

The method of mounting the elastic ring, as above described, has theadvantage of permitting the insertion o! the said ring alone and withoutany auxiliary sleeves. On the other hand, the elastic ring of congealedmaterial may be machined and worked in the same way as wood.

It may be subjected to the operations of drilling, cutting up, orboring, and it ls thus possible to bring it to the desired dimensionsand to give to it, in the congealed state, any desired form in order toassure a determined distribution of the elastic tensions when thiselastic material has resumed the surrounding temperature and to producecomplementary molecular tensions which are added, at given points orregions, to the tensions prevailing at the time of the congelation. Thusin the example represented in Fig. 2, there is formed in the end of theelastic ring 5, in the congealed state, an aperture Il which has theeilect oi modifying the distribution of the elastic tensions when thesaid ring has returned to the surrounding temperature. In fact. thetensions produced by eliminating the connections between the fibres ofthe end part l have a tendency to effects an increase of the pressureexercised by the elastic material I upon the end of the rod l and thewalls of the recess of the body I, at the upper part of this recess. Aparticular advantage of this disposition consists in the damping ofshocks and vibrations transmitted in the axial direction from the shankl to the body l of the insulator.

Obviously, the invention is not limited to the methods oi executionrepresented and described, which have been chosen solely by way ofexample.

Having now described my invention what I claim as new and desire tosecure by Letters Patent is:

1. In combination, an electric insulator comprising a cap o f insulatingmaterial provided with an inner irusto-conical recess havingsmoothwalls, the large base of said recess being directed towards the closedend o! the cap, a bracket having one end with a smooth surface ofcircular cross section extending in said recess and leaving a clearancebetween said bracket and said walls of said inner recess, a resilientmetallic sleeve provided with longitudinal slots arranged against saidwalls of said recess, and a ring of elastic material inserted in saidrecess between said bracket and said sleeve and considerably elongatedin the axial direction in compensation for a considerable compression ina radial direction.

2. In combination, an electric insulator comprislng a cap oi' insulatingmaterial provided with an inner recess having smooth walls of circularcross section, a metallic resilient sleeve provided with longitudinalslots arranged against said walls ci said recess, a bracket having oneend with a smooth surface of circular cross section extending in saidrecess and leaving a clearance between said bracket and said resilientsleeve, a ring of elastic material inserted in said recess between saidbracket and said resilient sleeve and considerably elongated in theaxial direction in compensation for a considerable compression in theradial direction, and stop means on said insulator adapted to maintainsaid metallic sleeve in said recess.

LECN THIRY.

increase the diameter of the oriiice il, which thus

